Extensible beam compass

ABSTRACT

Discloses an adjustable, extensible beam compass for drawing circles and arcs normal to the work and whose radii can be adjusted to range from minimal to the maximum extension of the compass. The compass has a handle member and inner extensible arms pivotally mounted, a pointer and an outer extensible arm pivotally mounted and a pencil-holding bracket and the other of the outer extensible arms pivotally mounted. One of the tubing members receives wedging members interposed between one of the inner extensible arms and one of the outer extensible arms, and the other tubing member receives wedging members interposed between the other inner extensible arm and the other outer extensible arm. Thumb-screw actuated movement of the wedging members releasably locks together the tubing members, extensible arms and wedging members.

United States Patent [191 Coil 1 1 EXTENSIBLE BEAM COMPASS Frederick J. Coil, 109 Latham Trailer Ct., Latham, NY. 12110 [22] Filed: May 1, 1974 [2]] Appl. No: 465,808

[76] Inventor:

[52] US. Cl 33/27 C; 33/152 R; 33/161 [51] Int. Cl B431 9/04 [58] Field of Search..... 33/27 C, 27 B, 27 F, 149 E, 33/149 F, 152 R, 152 B, 153 F, 156 B, 162,

Primary Examiner-Richard E. Aegerter Assistant ExaminerWi1lis Little Attorney, Agent, or Fz'rm-Walter F. Wessendorf, Jr.

1 1 June 3,1975

[57 1 ABSTRACT Discloses an adjustable, extensible beam compass for drawing circles and arcs normal to the work and whose radii can be adjusted to range from minimal to the maximum extension of the compass. The compass has a handle member and inner extensible arms pivotally mounted, a pointer and an outer extensible arm pivotally mounted and a pencil-holding bracket and the other of the outer extensible arms pivotally mounted. One of the tubing members receives wedg ing members interposed between one of the inner extensible arms and one of the outer extensible arms, and the other tubing member receives wedging members interposed between the other inner extensible arm and the other outer extensible arm. Thumb-screw actuated movement of the wedging members releasably locks together the tubing members, extensible arms and wedging members.

10 Claims, 7 Drawing Figures This invention relates to an extensible beam compass for use by a carpenter in drawing circles and arcs normal to the work surface such as rough wood.

The problems of the art to which the invention apertains are the need for an adjustable, extensible beam compass that can be used by a carpenter to accurately draw large circles and arcs normal to the work surface such as on rough wood, or on sidewalls near the ceiling, on the floors and on other surfaces and objects upon which the carpenter has need to draw large circles and arcs; the need for such an extensible beam compass that can be folded together for compact storage in the carpenter's tool box; the need for such an extensible beam compass which incorporates structural features that permit a carpenter to easily open the beam compass, to easily utilize the beam compass to accurately draw such large circles and arcs normal to the work surface, and to easily fold together the beam compass, after use, for compact storage in his carpenters tool box; and the need for such an extensible beam compass which incorporates structural features that permit the carpenter to adjust the beam compass to accurately draw circles and arcs normal to the work surface, and wherein the radii of the circles and arcs drawn can range from minimal to the maximum extension of the compass,

The objects of this invention, therefore, are to contribute to the solution of the discussed problems of the art by providing such an extensible beam compass that can thusly be utilized by a carpenter in his work.

These objects and other objects of the invention should be discerned and appreciated from the detailed specification taken in conjunction with the drawings, wherein like reference numerals refer to similar parts throughout the several views, in which:

FIG. 1 is a view of the invention;

FIG. 2 is a view of the invention taken in the direction of the arrows 2 2 in FIG. 1;

FIG. 3 is a view of the invention that represents a position of the invention for use in drawing small circles and arcs;

FIG. 4 is a view of the invention taken in the direction of the arrows 4 4 in FIG. 2;

FIG. 5 is a view of the invention taken in the direction of the arrows 5 5 in FIG. 4;

FIG. 6 is a view of the invention taken in the direction of the arrow 6 in FIG. 3; and

FIG. 7 is a view of the invention taken in the direction of the arrow 7 in FIG. 2.

To facilitate the understanding of the invention, a nomenclature list is hereby provided:

NOMENCLATURE 1 generally refers to the invention 3 handle member 5 depending segment from handle member 3 7 depending segment from arm 11 9 depending segment from arm 13 11 right, inner, elongated, extensible arm 13 left, inner, elongated, extensible arm 15 threaded pin 17 wing nut 19 right, hollow, square tubing member 21 left, hollow, square tubing member 23 right, outer, elongated, extensible arm 25 left. outer, elongated, extensible arm 27 top plate 29 screw 31 thumb screw 33 wedging member 35 L-shaped end block 37 screw 39 transversely extending shoulder portion of end block 35 41 depending finger thumb screw 45 pointer 47 threaded pin 49 wing nut 51 L-shaped, pencil-mounting bracket 53 threaded pin 55 wing nut 57 carpenters pencil S9 threaded hook of bracket 51 61 wing nut In FIG. 1 of the drawings, reference numeral 1 generally refers to the invention.

A handle member 3 has a depending segment 5 disposed between segments 7 and 9 integral with and depending from their respective right and left, inner, elongated, extensible arms 11 and 13, as viewed in FIG. 1 ofthe drawings. The segments 5, 7 and 9 are provided with a common bore through which a threaded pin 15 is disposed and whose threaded portion is appropriately engaged by a wing nut 17 to thereby pennit relative adjustment of the handle member 3 and extensible arms 11 and 13.

Right and left, inner, extensible arms 11 and 13 are slidably mounted and received within respective, right and left, hollow, square tubing members 19 and 21 which slidably mount and receive their respective, right and left, outer, elongated, extensible arms 23 and 25. Arms 11 and 13 are of identical construction, tubing members 19 and 21 are of identical construction, and arms 23 and 25 are of identical construction.

Each of the tubing members 19 and 21 has two identical top plates 27 fixed to the end top portions, as viewed in FIG. 1, of each of the tubing members 19 and 21. Each top plate 27 is fixed in its position, as shown, by two screws 29 disposed through appropriate holes formed in each plate 27 and engaged with aligned tapped holes formed in the top end portions of each of the tubing members 19 and 21. Each plate 27 has a tapped hole, formed in the bight portion between the holes receiving screws 29, that is engaged by a thumb screw 31 which also engages a tapped hole, aligned with the tapped hole in plate 27, that is formed in the top portion at the ends of each of the tubing members 19 and 21.

Each of the tubing members 19 and 21 receives therein two identical, elongated wedging members 33. In cross-section, each wedging member 33 has the configuration ofa right triangle. FIG. 5 shows the wedging members 33 disposed between the arms 11 and 23 adjacent to the lateral sidewalls of tubing member 19. The height of each of the wedging members 33 dimensionally is less than the height of either of the arms 11 and 23. After either, or both, of the arms 11 and 23 has been extended to the length desired, the arms 11 and 23 are locked in place within tubing member 19 by appropriate manipulation of the thumb screws 31 to effect thereby engagement of thumb screws 31 with the smallest side of one of the wedging members 33. Such engagement by thumb screws 31 will effect and cause relative movement of the wedging members along their common hypotenuses with resulting lateral bearing engagements of the wedging members 33 against arms ll and 23 which in turn will be constrained to bear against the lateral sidewalls of tubing member 19 with the re suit that tubing member 19. arms 11 and 23, and wedging members 33 will be locked together.

The description of the extensions of arms 11 and 23 to their desired lengths and their being locked together with tubing member 19 and wedging members 33 by appropriate manipulation of thumb screws 31 applies simiiarly to arms 13 and extended to their desired lengths and locked together by their interposed wedging members 33 within tubing member 21.

Lshaped end blocks are disposed in fixed rclationship within the ends ofthe tubing members 19 and 21 by means of screws 37. disposed through holes formed in the tubing members 19 and 21. that are appropriately engaged in aligned, tapped holes formed in the end blocks 35. Each of the end blocks 35 has a transversely extending shoulder portion 39. At one end of each of the elongated arms 11, 13, 23 and 25 is a depending finger 41. As shown more discernably in FIG. 4. shoulder portion 39 of end block 35 functions as a limit stop, upon abutment of depending finger 41 with shoulder portion 39 of arm 11, to prevent further outward extension of arm 11. Similarly. when the depending fingers 41 of arms 13. 23 and 25 are in abutting relationship with associated shoulder portions 39 of their respective end blocks 35, such respective shoulder por tions 39 similarly function as limit stops to limit any further outward extension of respective arms 13, 23 and 25.

Thumb screws 43, appropriately engaged with aligned tapped holes formed in the bottom ends of tubing members 19 and 21, and shoulder portions 39, slightly bear against the bottoms of elongated arms 11, i3. 23 and 25, and, as such. function to steady the extensible arms within their respective tubing members.

A pointer 45 having a sharp point is adjustably mounted at one end of arm 25 in pivotal mounting relationship therewith. Pointer 45 and arm 25 have a common bore through which a threaded pin 47 is disposed and whose threaded portion is appropriately engaged by a wing nut 49 to thereby permit such adjustment of pointer 45 relative to arm 25.

An L-shaped, pencil-mounting bracket 51 is adjust ably mounted at one end of arm 23 in pivotal mounting relationship therewith. Bracket 51 and arm 23 having a common bore through which athreaded pin 53 is dis posed and whose threaded portion is appropriately engaged by a wing nut 55 to thereby permit such adjustment of bracket 51 relative to arm 23.

A carpenter's pencil 57 is adjustably mounted and carried by means of threaded hooks 59 disposed through holes formed in bracket 51. The threaded portions of books 59 are appropriately engaged by wing nuts 61.

From the foregoing description. it should be discerned and appreciated that the extensible beam com pass of this invention can be utilized to draw circles and arcs whose radii range from minimum to the maximum extension of the compass. For drawing minimal-size circles and arcs having minimal radii. the compass would approximate the position represented by FIG. 3

4 with corresponding pivotal adjustments made in the pointer 45 and bracket 51 in order that the circle or are will be drawn with both the pointer 45 and pencil 57 normal to the work surface to facilitate drawing of the circle or are and to assure that the circle or are drawn will be accurate.

FIG. 1 of the drawings represents a position of the compass utilized to draw a circle or are whose radius is within the minimum to maximum radii ranges of the compass. with the corresponding pivotal adjustments made in the pointer 45 and bracket 51 in order that the circle or are will be drawn with both the pointer 45 and pencil 57 normal to the work surface to facilitate drawing the circle or are and to assure accuracy thereof.

To utilize the compass to draw a circle or are of the maximum radius permitted by the compass, the arms 11, 13, 23 and 25 are extended to their fullest and thumb screws 31 are appropriately manipulated to lock the arms 11 and 23, and 13 and 25, together with their respective tubing members 19 and 21, and wedging members 33.

Whether the compass is utilized to draw small or large circles or arcs, the thumb screws 31 engageable with wedging members 33 permit the extensible arms and tubing members to be locked together to assure that whatever size circle or are that is drawn will be ac curate.

From the descriptions of the use of the compass to draw circles or arcs, it should be appreciated that the compass. after use, can be easily folded together for compact storage in the carpenters tool box.

Having thusly described my invention, 1 claim;

1. An adjustable. extensible beam compass for drawing circles and arcs normal to the work surface and whose radii can range from minimum to the maximum extension of said compass, said compass comprising tubing members, extensible arms, wedging members, a handle member, a pointer and a bracket. said tubing members each receiving therein end portions of said extensible arms which overlap and tapered wedging members, interposed said extensible arms said tubing members carrying means operable to move said wedging members to releasably lock together said extensible arms, wedging members and tubing members, means pivotally mounting said arms and said handle member, means pivotally mounting one of said arms and said pointer, means pivotally mounting one of said arms and said bracket, and said bracket having means for adjustably mounting and carrying a pencil.

2. An adjustable, extensible beam compass in accordance with claim 1, wherein each of said wedging members, in cross-section, is in the configuration of a right triangle. and wherein, upon appropriate locking movement of said wedging members along their common hypotenuses, said wedging members bear against said arms and cause said arms to bear against said tubing members.

3. An adjustable. extensible beam compass in accordance with claim 1. wherein said means. carried by said tubing members and operable to move said wcdging members. comprise screws engaged with said wcdging members.

4. An adjustable, extensible beam compass in accordance with claim 1, wherein each of said wedging members, in cross-section. is in the configuration of a right triangle. and wherein. upon appropriate locking move ment. of said wedging members along their common hypotenuses, said wedging members bear against said arms and cause said arms to bear against said tubing members; and wherein said means, carried by said tubing members and operable to move said wedging members, comprise screws engaged with said wedging members.

S. An adjustable, extensible beam compass in accordance with claim I, wherein said tubing members carry end blocks, wherein said end blocks have shoulder portions, wherein said arms have depending fingers, and wherein said shoulder portions, upon abutment therewith of said depending fingers, function as limit stops to prevent further outward extension of said arms from said tubing members.

6. An adjustable, extensible beam compass in accordance with claim 1, wherein said tubing members carry screws and wherein said screws bear slightly against said arms to steady arms within said tubing members.

7. An adjustable, extensible beam compass in accordance with claim 1, wherein said extensible arms are inner arms and outer arms, and wherein each of said tubing members receives therein an inner arm and an outer arm.

8. An adjustable, extensible beam compass in accordance with claim 1, wherein said handle member has a depending segment, wherein said arms have depending segments, wherein each handle member depending segment is disposed between said depending segments of said arms, and wherein said means pivotally mounting said arms and said handle member comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said segments.

9. An adjustable, extensible beam compass in accordance with claim 1, wherein said means pivotally mounting one of said arms and said pointer comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said pointer, and wherein said means pivotally mounting one of said arms and said bracket comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said bracket.

10. An adjustable, extensible beam compass in accordance with claim 1, wherein each of said wedging members, in cross-section, is in the configuration of a right triangle, and wherein, upon appropriate locking movement of said wedging members along their common hypotenuses, said wedging members bear against said arms and cause said arms to bear against said tubing members; wherein said means, carried by said tubing members and operable to move said wedging members, comprise screws engaged with said wedging members; wherein said tubing members carry end blocks, wherein said end blocks have shoulder portions, wherein said arms have depending fingers, and wherein said shoulder portions, upon abutment therewith of said depending fingers, function as limit stops to prevent further outward extension of said arms from said tubing members; wherein said tubing members carry screws and wherein said screws bear slightly against said arms to steady said arms within said tubing members; wherein said extensible arms are inner arms and outer arms, and wherein each of said tubing members receives therein one of said inner arms and one of said outer arms; wherein said handle member has a depending segment, wherein said arms having depending segments, wherein said handle member depending segment is disposed between said depending segments of said arms, and wherein said means pivotally mounting said arms and said handle member comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said segments; and wherein said means pivotally mounting one of said arms and said pointer comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said pointer, and wherein said means pivotally mounting one of said arms and said bracket comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said bracket. 

1. An adjustable, extensible beam compass for drawing circles and arcs normal to the work surface and whose radii can range from minimum to the maximum extension of said compass; said compass comprising tubing members, extensible arms, wedging members, a handle member, a pointer and a bracket; said tubing members each receiving therein end portions of said extensible arms which overlap and tapered wedging members, interposed said extensible arms said tubing members carrying means operable to move said wedging members to releasably lock together said extensible arms, wedging members and tubing members, means pivotally mounting said arms and said handle member, means pivotally mounting one of said arms and said pointer, means pivotally mounting one of said arms and said bracket, and said bracket having means for adjustably mounting and carrying a pencil.
 1. An adjustable, extensible beam compass for drawing circles and arcs normal to the work surface and whose radii can range from minimum to the maximum extension of said compass; said compass comprising tubing members, extensible arms, wedging members, a handle member, a pointer and a bracket; said tubing members each receiving therein end portions of said extensible arms which overlap and tapered wedging members, interposed said extensible arms said tubing members carrying means operable to move said wedging members to releasably lock together said extensible arms, wedging members and tubing members, means pivotally mounting said arms and said handle member, means pivotally mounting one of said arms and said pointer, means pivotally mounting one of said arms and said bracket, and said bracket having means for adjustably mounting and carrying a pencil.
 2. An adjustable, extensible beam compass in accordance with claim 1, wherein each of said wedging members, in cross-section, is in the configuration of a right triangle, and wherein, upon appropriate locking movement of said wedging members along their common hypotenuses, said wedging members bear against said arms and cause said arms to bear against said tubing members.
 3. An adjustable, extensible beam compass in accordance with claim 1, wherein said means, carried by said tubing members and operable to move said wedging members, comprise screws engaged with said wedging members.
 4. An adjustable, extensible beam compass in accordance with claim 1, wherein each of said wedging members, in cross-section, is in the configuration of a right triangle, and wherein, upon appropriate locking movement of said wedging members along their common hypotenuses, said wedging members bear against said arms and cause said arms to bear against said tubing members; and wherein said means, carried by said tubing members and operable to move said wedging members, comprise screws engaged with said wedging members.
 5. An adjustable, extensible beam compass in accordance with claim 1, wherein said tubing members carry end blocks, wherein said end blocks have shoulder portions, wherein said arms have depending fingers, and wherein said shoulder portions, upon abutment therewith of said depending fingers, function as limit stops to prevent further outward extension of said arms from said tubing members.
 6. An adjustable, extensible beam compass in accordance with claim 1, wherein said tubing members carry screws and wherein said screws bear slightly against said arms to steady arms within said tubing members.
 7. An adjustable, extensible beam compass in accordance with claim 1, wherein said extensible arms are inner arms and outer arms, and wherein each of said tubing members receives therein an inner arm and an outer arm.
 8. An adjustable, extensible beam compass in accordance with claim 1, wherein said handle member has a depending segment, wherein said arms have depending segments, wherein each handle member depending segment is disposed between said depending segments of said arms, and wherein said means pivotally mounting said arms and said handle member comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said segments.
 9. An adjustable, extensible beam compass in accordance with claim 1, wherein said means pivotally mounting one of said arms and said pointer comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said pointer, and wherein said means pivotally mounting one of said arms and said Bracket comprises a threaded pin, engaged by a wing nut, disposed through a common bore in said arm and said bracket. 